There is a good deal of information on the web explaining why the EV model does not scale and does not perform well under load.

No amount of indexing will fix the basic flaw in the EV design.

Some people are fooled by the relative decent performance for single row and related row set retrieval but it is very easy to find fairly simple queries that do not run well with this design. Once you get 250 million rows of EV values like an application we purchased has you can pretty much schedule vacation while you wait for results.

-- Mark D Powell --